scholarly journals Preparation of Cellulose-based fluorescent materials as coating pigment by use of reversible DMSO/DBU/CO2 system

Author(s):  
Qinghua Cao ◽  
Jinyue Dai ◽  
Xin Bao ◽  
Zhenyu Zhang ◽  
Fei Liu ◽  
...  

Abstract A series of cellulose-based fluorescent materials are prepared under relative mild condition by use of the particular reversible DMSO/DBU/CO2 system to utilize as coating pigments. Through the observation under 365nm UV light, the cellulose-based fluorescent materials exhibit good fluorescence response and bright color. Furthermore, due to the limitation of the molecular skeleton of cellulose, the intrinsic aggregation caused quenching phenomenon commonly existed in conventional organic fluorescent pigments can be effectively inhibited, which is very helpful to retain good fluorescence response in epoxy-based coating material and its coating films. Moreover, the addition of cellulose-based fluorescent materials also increases the mechanical properties of the coating film. The increase of tensile strength and tensile modulus respectively reaches ~ 39% and ~ 66%. Solvent resistance and thermal property of the coating films generally remain unchanged. The fabrication of cellulose-based fluorescent materials in DMSO/DBU/CO2 system provides a feasible way to develop the functional application of cellulose.

2021 ◽  
Author(s):  
Qinghua Cao ◽  
Jinyue Dai ◽  
Xin Bao ◽  
Zhenyu Zhang ◽  
Fei Liu ◽  
...  

Abstract A series of cellulose-based fluorescent materials are prepared under relative mild conditions by use of the DMSO/DBU/CO2 system to utilize as coating pigments. Through the observation under 365nm UV light, the cellulose-based fluorescent materials exhibit good fluorescence response and bright color. Furthermore, due to the limitation of the molecular skeleton of cellulose, the intrinsic aggregation caused quenching phenomenon commonly existed in conventional organic fluorescent pigments can be effectively inhibited, which is very helpful to retain good fluorescence response in epoxy-based coating material and its coating films. Moreover, the addition of cellulose-based fluorescent materials also increases the mechanical properties of the coating film. The increase of tensile strength and tensile modulus respectively reaches ~39% and ~66%. Solvent resistance and thermal property of the coating films generally remain unchanged. The fabrication of cellulose-based fluorescent materials in DMSO/DBU/CO2 system provides a feasible way to develop the functional application of cellulose.


2021 ◽  
Author(s):  
Qinghua Cao ◽  
Jinyue Dai ◽  
Xin Bao ◽  
Zhenyu Zhang ◽  
Fei Liu ◽  
...  

Abstract A series of cellulose-based fluorescent materials are prepared under relative mild conditions by use of the reversible DMSO/DBU/CO2 system to utilize as coating pigments. Through the observation under 365nm UV light, the cellulose-based fluorescent materials exhibit good fluorescence response and bright color. Furthermore, due to the limitation of the molecular skeleton of cellulose, the intrinsic aggregation caused quenching phenomenon commonly existed in conventional organic fluorescent pigments can be effectively inhibited, which is very helpful to retain good fluorescence response in epoxy-based coating material and its coating films. Moreover, the addition of cellulose-based fluorescent materials also increases the mechanical properties of the coating film. The increase of tensile strength and tensile modulus respectively reaches ~ 39% and ~ 66%. Solvent resistance and thermal property of the coating films generally remain unchanged. The fabrication of cellulose-based fluorescent materials in DMSO/DBU/CO2 system provides a feasible way to develop the functional application of cellulose.


2017 ◽  
Vol 737 ◽  
pp. 209-213 ◽  
Author(s):  
Rittichai Sangkatip ◽  
Wipoo Sriseubsai ◽  
Kunlanan Kiatkittipong

The aim of this present work is to enhance photoantibacterial performance on a surface of Acrylonitrile-Butadiene-Styrene (ABS) by mixing titanium dioxide (TiO2). The influences of different ratios for TiO2 under UV light irradiation were investigated according to JIS Z 2801: 2010 standard. 0.5%, 1% and 2% TiO2/ABS were formed by melting process with internal mixer and compression molding process. E.coli were chosen as a model of bacteria. The best photoantibacterial activity was provided by 0.5% TiO2/ABS. The result showed that E.coli could reduce up to 46.95%. However, a higher amount of TiO2 (i.e., 1% and 2% TiO2/ABS) obstructed the reaction, and E.coli was reduced to 42.6% and 36.08%, respectively. This was due to its aggregation observed from SEM image. For mechanical properties for TiO2/ABS, The results showed that tensile modulus and tensile strength of blending TiO2 at 0.5 %wt was the highest but the tensile was decreased when increasing TiO2 in polymer blended.


2014 ◽  
Vol 1025-1026 ◽  
pp. 215-220 ◽  
Author(s):  
Sasirada Weerasunthorn ◽  
Pranut Potiyaraj

Fumed silica particles (SiO2) were directly added into poly (butylene succinate) (PBS) by melt mixing process. The effects of amount of fumed silica particles on mechanical properties of PBS/fumed silica composites, those are tensile strength, tensile modulus, impact strength as well as flexural strength, were investigated. It was found that the mechanical properties decreased with increasing fumed silica loading (0-3 wt%). In order to increase polymer-filler interaction, fumed silica was treated with 3-glycidyloxypropyl trimethoxysilane (GPMS), and its structure was analyzed by FT-IR spectrophotometry. The PBS/modified was found to possess better tensile strength, tensile modulus, impact strength and flexural strength that those of PBS/fumed silica composites.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 698
Author(s):  
Selin Sökmen ◽  
Katja Oßwald ◽  
Katrin Reincke ◽  
Sybill Ilisch

High compatibility and good rubber–filler interactions are required in order to obtain high quality products. Rubber–filler and filler–filler interactions can be influenced by various material factors, such as the presence of processing aids. Although different processing aids, especially the plasticizers, and their effects on compatibility have been investigated in the literature, their influence on rubber–filler interactions in highly active filler reinforced mixtures is not explicit and has not been investigated in depth. For this purpose, the influence of treated distillate aromatic extract (TDAE) oil content and its addition time on interactions between silica and rubber chains were investigated in this study. Rubber–filler and filler–filler interactions of uncured and cured silica-filled SBR/BR blends were characterized by using rubber layer L concept and dynamic mechanical analysis, whereas mechanical properties were studied by tensile test and Shore A hardness. Five parts per hundred rubber (phr) TDAE addition at 0, 1.5, and 3 min of mixing were characterized to investigate the influence of TDAE addition time on rubber–filler interactions. It was observed that addition time of TDAE can influence the development of bounded rubber structure and the interfacial interactions, especially at short time of mixing, less than 5 min. Oil addition with silica at 1.5 min of mixing resulted in fast rubber layer development and a small reduction in storage shear modulus of uncured blends. The influence of oil content on rubber–filler and filler–filler interactions were investigated for the binary blends without oil, with 5 and 20 phr TDAE content. The addition of 5 phr oil resulted in a slight increase in rubber layer and 0.05 MPa reduction in Payne effect of uncured blends. The storage tensile modulus of vulcanizates at small strains decreased from 13.97 to 8.28 MPa after oil addition. Twenty parts per hundred rubber (phr) oil addition to binary blends caused rubber layer L to decrease from 0.45 to 0.42. The storage tensile modulus of the vulcanizates and its reduction with higher amplitudes were incontrovertibly high among the vulcanizates with lower oil content, which were 13.57 and 4.49 MPa, respectively. When any consequential change in mechanical properties of styrene–butadiene rubber (SBR)/butadiene rubber (BR) blends could not be observed at different TDAE addition time, increasing amount of oil in blends enhanced elongation at break, and decreased Shore A hardness and tensile strength.


2021 ◽  
Vol 10 (1) ◽  
pp. 403-411
Author(s):  
Youliang Cheng ◽  
Mingjie Wang ◽  
Changqing Fang ◽  
Ying Wei ◽  
Jing Chen ◽  
...  

Abstract To change the optical properties and improve the antibacterial performances of carbon quantum dots (CQDs) and Ag NPs, mesoporous SiO2 spheres were combined with them to form the composites. In this paper, CQDs with a uniform size of about 3.74 nm were synthesized using glucose as carbon source. Then, CQDs/mesoporous SiO2/Ag NPs composites were obtained in situ under UV light irradiating by using mesoporous SiO2 and Ag NO3 as the carrier and silver resource, respectively. The diameter of CQDs/mesoporous SiO2/Ag NPs particles was in the range of 200–250 nm. With the increase in irradiating time, the red-shift in the UV-Vis spectrum for as-prepared CQDs/mesoporous SiO2/Ag NPs composites was found, and the adsorption peak was widened. In addition, the composites showed a high antibacterial activity against Staphylococcus aureus and Escherichia coli via disc diffusion method. These results indicated that inhibition circles for Ag NPs/mesoporous SiO2/CQDs and mesoporous SiO2/Ag NPs were similar in diameter. Furthermore, the two composites had a better bactericidal performance compared with other particles. Therefore, as-prepared CQDs/mesoporous SiO2/Ag NPs composites in this paper have great potential applications for fluorescent materials and antibacterial materials.


2020 ◽  
Vol 35 (1) ◽  
pp. 61-70
Author(s):  
Na Young Park ◽  
Young Chan Ko ◽  
Lili Melani ◽  
Hyoung Jin Kim

AbstractFor the mechanical properties of paper, tensile testing has been widely used. Among the tensile properties, the tensile stiffness has been used to determine the softness of low-density paper. The lower tensile stiffness, the greater softness of paper. Because the elastic region may not be clearly defined in a load-elongation curve, it is suggested to use the tensile modulus which is defined as the slope between the two points in the curve. The two points which provide the best correlation with subjective softness evaluation should be selected. Low-density paper has a much lower tensile strength, but much larger elongation at the break. It undergoes a continuous structural change during mechanical testing. The degree of the structural change should depend on tensile conditions such as the sample size, the gauge length, and the rate of elongation. For low-density paper, the tensile modulus and the tensile strength should be independent of each other. The structure efficiency factor (SEF) is defined as a ratio of the tensile strength to the tensile modulus and it may be used a guideline in developing superior low-density paper products.


2021 ◽  
Vol 30 ◽  
pp. 263498332110074
Author(s):  
Henry C Obasi ◽  
Uchechi C Mark ◽  
Udochukwu Mark

Conventional inorganic fillers are widely used as fillers for polymer-based composites. Though, their processing difficulties and cost have demanded the quest for credible alternatives of organic origin like coconut shell fillers. Dried shells of coconut were burnt, ground, and sifted to sizes of 63, 150, 300, and 425 µm. The ground coconut shell particles (CSP) were used as a filler to prepare polypropylene (PP) composites at filler contents of 0% to 40% via injection melt blending process to produce PP composite sheets. The effect of the filler particle size on the mechanical properties was investigated. The decrease in the size of filler (CSP) was found to improve the yield strength, tensile strength, tensile modulus, flexural strength, flexural modulus, and hardness of PP by 8.5 MPa, 15.75 MPa, 1.72 GPa, 7.5 MPa, 100 MPa, and 10.5 HR for 63 µm at 40%, respectively. However, the elongation at break and modulus of resilience of the PP composites were seen to increase with increase in the filler size. Scanning electron microscope analysis showed that fillers with 63 µm particle size had the best distribution and interaction with the PP matrix resulting in enhanced properties.


2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Abdullah Mohammed Ali Mohammed Altaweel ◽  
Jaya Madhu Raj ◽  
Malalvalli Nagarajaiah Chandrashekara ◽  
Puttegowda Ramya ◽  
Parthasarathy Sampathkumaran ◽  
...  

Abstract Polystyrene (PS) based composites respectively with cenosphere (CS) and calcium aluminosilicate (CAS) as fillers were studied using the positron lifetime technique to reveal the correlation between free volume, a microstructural property, and mechanical properties of the composites (tensile strength and tensile modulus). The thermal stability of the composites was determined using differential scanning calorimetry. The results showed that addition of CAS filler lead to a significant improvement in the mechanical properties of the composite, whereas addition of CS resulted in improvement in tensile modulus only. Both PS/CAS and PS/CS composites showed enhancement in thermal stability compared with that of the pure PS matrix. The positron results showed that the average free volume size for the PS/CAS composite (at 40 phr CAS) was reduced significantly compared with that of the pure PS. These results are understood in terms of the influence of silica content, filler-matrix interaction, and particle size.


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